Manholes are surface access points for underground utilities, and other infrastructure features. Manholes typically comprise a metal ring into which a metal cover is placed. The cover is removed to allow access to the manhole. Most manholes are round because the diameter of the cover is always larger than the diameter of the manhole, and therefore the cover cannot pass into the manhole. However, some manholes have other shapes, such as square or rectangle.
In order to ensure a tight fit between the manhole and the cover, the manhole typically has sharp edges in the ring. The sharp edges, however, over time can damage equipment that is lowered into the manhole, for example hoses and cables, as well as other pieces of equipment, such as tools, sensors, test devices, etc. The sharp edges can cut into/or cause fraying of the hose and cables, as well as damage other equipment, and thus render them unusable, requiring replacement. The sharp edges may also injure personnel as they enter or exit the manhole.
This problem is particularly prevalent for rescue personnel that are conducting emergency services inside a manhole. The rescue personnel need to quickly lower/raise equipment, cables, hoses, personnel, etc. into the manhole to provide services such as fire suppression and medical rescue of civilians.
Currently, ad-hoc measures are taken to attempt to protect equipment, such as using articles of clothing, e.g. firefighter's jackets, or pieces of fire hose, to line a portion of the manhole. However, as items are raised/lowered in the manhole, the ad-hoc measures typically fall into the manhole. Other measures include using a roller system that is placed adjacent to the manhole. To prevent the roller system from falling into the manhole, the roller system is typically spiked into the road. This undesirably damages the road. Also, the roller system only covers a portion of the manhole, leaving the ring exposed on other portions.